Gas-engine.



A. H.- THOMAS.

GAS ENGINE.

APPLICATION FILED OCT. 11, 1906.

Patented Nov. 21, 1911.

UNITED STATES PATENT OFFICE.

ALBERT H. THOMAS, OF SPRINGFIELD, OHIO, ASSIGNOR '10 GEORGE B. SWOPE, OF

I SPRINGFIELD, OHIO.

GAS-ENGINE.

Specification of Letters Patent.

Patented Nov. '21, 1911.

Application filed October 11, 1906. Serial No. 338,505.

To all whom it may concern:

Be it known that I, ALBERT H. THOMAS, a citizen of the United States, and a resident of Springfield, in the county of Clark and State of Ohio, have invented a certain new and useful Improvement in Gas-Em gines, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of my specification.

My invention relates to a gas engine, and more particularly to the mechanism for controlling the valves of such an engine. Its object is to produce a simple, positively acting valve gear without cog wheels or other complicated mechanism, which are eX- pensive to make, and apt to get out of order, and require adjustment.

The advantages of my invention will appear as I proceed with my specification.

In the drawings :Figure 1 is a top plan View of a gas engine, showing my improved valve mechanism; Fig. 2 is a front view of said mechanism, showing the parts in the position in which the valve is closed; Fig. 3 is a similar view showing the position of the mechanism when the valve is about to open; Fig. 4 is a side elevation of Fig. 3; and Fig. 5 is a side elevation showing the valve mechanism when the valve is open.

I have illustrated my improvement by showing it in connection with a single cylinder, four cycle gas engine, but of course, I do not wish to limit it to this particular type of engine, as it will be apparent that it may be applied to any four cycle gas englne.

In the drawings, A is the bed of the machine, B is the fly-wheel, O the driving shaft, and D is the crank-pin.

E is the rod which opens the valve, said rod being supported in suitable brackets E, attached to the frame of the engine.

F is a cylindrical drum keyed to the driven shaft C. There is formed on this drum in line with the end of the rod E, an eccentric F, which is of such shape that for half of a revolution it will cause and maintain a full throw of the mechanism now to be described. At one side of this eccentric, a groove f is formed in the drum F, which passes around said drum twice in the following manner :--Beginning at a point in the face of the drum in line with the point where the surface of the eccentric coincides with the surface of the drum, the groove passes around the drum in a plane at right angles to theaxis of said drum for half a revolution, then runs diagonally across the face of said drum toward its opposite end, such crossing taking half a revolution, and then for another half revolution travels substantially parallel to its first passage, then crosses back diagonally so as to cross its first path, as indicated at f, to the starting point, said crossing taking another halfrevolution. This groove thus passes around the drum twice in completing its path, and is for the purpose of controlling the movement of a lever, which at intervals is interposed between the eccentrio F and the rod E, and which operates the said rod E. G is the said lever, which carries at one end a roller G adapted to engage the eccentric F, and near its other end is pivoted to a swinging arm J, which is pivoted at J to the frame A, immediately below the shaft C, in a vertical position, tangential to the drum F. At the upper end of the arm J is pivoted a shoe j which travels in the groove f. A coil-spring g normally holds the lever G in position, so that the roller Gr contacts with the drum F, but leaves said arm free to move on its axis independently of the swinging arm J, when it strikes the eccentric F. The groove is perfectly rounded out at the cross-over, so that there may be no drag of the roller G in the direction of the length of the drum, as it passes over the eccentric F, which of course reduces friction, and tends to the accurate operation of the mechanism.

It is apparent from the description that beginning with the position of the shoe in Figs. 3 and 4 during half a rotation of the drum F, the roller G will be operated upon by the eccentric F, so as to bring the upper end of the lever G into engagement with the end of the rod E, and that during half of this time, or during a quarter of a revolution, the rod E will be held at the limit of its motion, as indicated at Fig. 5, thus holding the exhaust valve completely open at that time; at the end of the first half revolution the shoe 7', by reason of its travel in the groove y, will immediately swing the arm J and with it the lever G out of the path of the eccentric F, so as to prevent the I prefer to provide the jump spark system for the electric spark in connection with the valve controlling mechanism, as in this way I can insure its operation at the proper time. To this end I secure a flat spring wiper-bar K to the side of the swinging arm J, as indicated at 72, said wiper-bar being insulated from the arm J, and thus from the rest of the engine. A pin is is located on the drum F, in a position to strike said spring as the shoe 7' brings said spring into its neighborhood. By this arrangement also, the contacts are self-cleaning, as the pin, by its continual wiping action against the bar K removes all dirt of any sort whatever, and a clean electrical contact is thus always insured.

Having described my invention, what I desire to claim as new and cover by Letters Patent, is

In a gas engine of the class described, a combination of a driving shaft and valve with means for controlling the operation of said valve including a valve rod, a drum secured to the shaft, an eccentric adjacent to said drum, grooves in the face of the drum, an arm pivotally mounted and projecting toward the driving shaft and tangential to said driving shaft and capable of'being swung on its pivot, a shoe carried by said arm capable of fitting in the groove in the shaft at a point substantially in line with the center of the shaft, a supplemental arm pivotally mounted on the first mentioned arm and a roller on the end of said last mentioned arm adapted to engage the eccentric, substantially as specified.

ALBERT H. THOMAS.

Witnesses:

CHARLES W. FOSTER, WALTER C. PIERCE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

